The symptoms of Lyme disease, whether early or late stage, may be non-specific and easily missed or misdiagnosed. Diagnosis should be clinical, taking into account medical history, signs, symptoms and tick-exposure risk. Since patients may omit to mention a tick bite or unusual skin rash, a detailed clinical history is essential. A travel history is particularly important; there are many regions of Europe and North America where borrelia-infected ticks are highly prevalent. Infection is most likely to occur between late spring and early autumn. (For details see Introduction - epidemiology.)

Lyme serology may be supportive, though a negative test result does not necessarily exclude the diagnosis.

Lyme disease is not notifiable in the UK, however, occupationally acquired cases should be reported via RIDDOR.

Erythema migrans (EM) rash

An EM rash is diagnostic of Lyme disease. However, at least 30% of UK patients may have no rash and may not recall a tick bite. It usually develops within three to 30 days of a tick bite, may not be a typical bull’s eye and may be difficult to differentiate from insect bites. It is not usually hot or itchy and may be distant from the site of the bite. There may be multiple lesions. It may be misdiagnosed as ringworm, cellulitis or other skin conditions and is usually greater than five centimetres in diameter.

In pigmented skin, the erythema may be more difficult to identify. The EM rash may have red, purple or blue hues, or appear as a hyper-pigmented rash.

If uncertain, seek an urgent specialist opinion and consider punch biopsy for molecular (PCR) testing. Avoid any undue delay in initiating treatment.

NICE: Erythema migrans images

CDC: erythema migrans images

Early Lyme disease

This may present with flu-like symptoms ‘out of season’ (with or without an EM rash), for example, fever and sweats, lymphadenopathy, malaise, fatigue, neck pain, migratory myalgia or arthralgia, brain fog, headaches paraesthesia.

It has been documented that borrelia may disseminate through the body at an early stage. Lyme serology may be negative - this does not exclude the diagnosis. Routine blood tests, including inflammatory markers, are usually normal.

Late Lyme Disease

Lyme disease may present with acute or chronic multi-systemic signs and symptoms, weeks, months or even years later, if not diagnosed early. For example:

  • facial palsy
  • meningitis
  • dizziness
  • unexplained radiculopathy
  • encephalitis
  • neuropsychiatric presentations
  • inflammatory arthritis
  • neurological conditions
  • cardiac problems
  • ME/CFS
  • fibromyalgia
  • uveitis or keratitis
  • skin rashes

Diagnosis at this stage may be difficult. Negative serology does not exclude the diagnosis.

Life-threatening and even fatal outcomes such as sudden cardiac arrest and suicide have been reported. These are considered to be rare occurrences, though their true incidence is unknown.

Sudden Cardiac Deaths Associated with Lyme Carditis

Suicide and Lyme disease

Some patients may present with a self-diagnosis of early, late or chronic Lyme disease. These concerns should be investigated appropriately. (In 2017 - only 75% of laboratory confirmed Lyme cases were recorded as ‘acute’.)


Several national and international organisations have produced guidelines:

Paediatric Lyme disease

Children of all ages are potentially at risk. 60% of tick bites on children are above the waist. Ticks can attach in the hairline and on the scalp of children and remain undetected for longer than on adults. Facial palsy with headache and fever has been shown to predict early Lyme disease in children during peak Lyme disease season in endemic areas (May – Oct). In children, anxiety, emotional disorders and difficulties with attention and learning that interfere with school performance may develop if Lyme disease is undetected or untreated.

Imperial College NHS Trust - Lyme disease in children [PDF]

Congenital Lyme disease

The possibility of congenital Lyme disease is a known uncertainty at systematic review level and requires further research. James Lind Alliance's Lyme disease top ten uncertainties.

  • CDC (USA) states: 'Lyme disease acquired during pregnancy may lead to infection of the placenta and possible stillbirth; however, no negative effects on the fetus have been found when the mother receives appropriate antibiotic treatment. There are no reports of Lyme disease transmission from breast milk.'
  • No characteristic pattern of congenital abnormality has been documented in infants of mothers with Lyme disease.
  • It is important to treat a pregnant woman presenting with Lyme disease with antibiotics according to usual practice. Antibiotics such as doxycycline that are contraindicated in pregnancy should be avoided.
  • If a woman contracts Lyme disease during pregnancy, it is advisable to speak to a paediatric infectious disease specialist well in advance of delivery. This will enable consideration to be given to placental and cord blood studies and appropriate follow up of the infant.